Okay everyone, today I'm talking about periods and menstruation. Why is a dietitian talking about this you ask? I'm talking about it because women are made to feel fearful about our eating, especially around our periods. When we are more hungry before our period, also known as 'that time of the month,' or however you want to say it, we might think it's all in our head, we're using it as an excuse, or we just try to suffer through it and ignore our hunger.
Here's the thing though- your energy needs are dynamic- they change day to day, based on many different factors, one of which for women is what part of your cycle you're in! That's right, your energy needs change throughout your cycle and you need more energy before your period- it's not just in your head!!
First- a quick recap of menstruation
Okay everyone, we're going back to high school biology for a minute here- in order to talk about energy needs during our period, we need a recap on what's going on! There are four basic phases of menstruation, which on average is 28 days.
Menstrual phase- (Your period.)
The shedding of the lining of your uterus starts your menstruation cycle. This typically lasts anywhere from 4-7 days. Since blood is lost, this is why women who are menstruating have a higher iron requirement (18mg per day vs. 8mg per day for men and post-menopausal women!)
Follicular phase- Days 1-13 (When your body gets the egg ready to be released and prepares the lining of your uterus)
This is when a follicle in your ovary gets ready to release an egg, which takes around 13 days to mature. Your body will start rebuilding your the lining of your uterus to get ready to for the egg if it is fertilized.
Ovulation- Day 14 (When the egg is actually released)
This is when the egg is released from the follicle to be fertilized, caused by a spike in estrogen and other hormones. During this time, your body temperature will go up slightly- this is how some women monitor their fertility by checking their basal body temperature.
Luteal phase- Days 15-28 (Before your period! When people talk about PMS, it would happen during this phase!)
The egg makes its way through the fallopian tube over a 24 hour period. If it is not fertilized, it will begin to break down. Progesterone helps keep the uterine lining thick but drops by the end of the cycle, beginning the shedding of the lining of the uterus and the next menstrual cycle if the egg was not fertilized.
Image source: menstrupedia.com
So how does this play into appetite?
When progesterone gets released during the luteal phase (after ovulation, before your period), appetite and energy expenditure go up! We don't know for sure that progesterone is the cause of this but there is the correlation. Your body temperature also goes up slightly during this phase, which might partially account for the increased energy expenditure.
Anyways, this means during the luteal phase, ie. before your period, you're more hungry because your body needs more energy!!
Research estimates your energy needs to be anywhere from ~5-10% higher before your period (during the luteal phase) than after your period (during the follicular phase.) You can find these studies here and here. Some research has shown intakes in women are as much as 500 calories higher before their period! There is a wide variation in individuals when we look at the increase in metabolic rate and hunger- pay attention to your hunger and trust your body's signals!
Everyone is different in terms of what happens with their body. Maybe you don't notice you're more hungry before your period- that's okay too! What I'm getting at here isn't that you need to eat xxx more calories before your period but rather that if you do notice you're more hungry, it's important to trust what your body is telling you.
What about cravings?
So what about cravings, like for chocolate? Some research suggests the craving for chocolate might be cause partially by the drop in estrogen and progesterone, which happen right before menstruation. These can cause mood changes and stress, thus leading us to use chocolate to cope. Chocolate cravings continue after menopause for many women so the hormone fluctuations are probably not the only factor leading to chocolate cravings!
So what is my outlook on cravings? If it is really what you want, then enjoy it! Restriction and deprivation eventually lead to overeating, which is followed by guilt and more restriction. It's a vicious cycle. So if you're having a craving, take a step back and ask yourself what you're hungry for. If what you really want is chocolate for example, then eat the chocolate- if you can eat it mindfully and slow down and really enjoy the flavours and textures, you'll probably enjoy it even more!
When I was looking through the research, unfortunately I wasn't able to find any studies looking at cravings and menstruation that controlled for dieting and restriction. My guess would be that cravings would be higher in those who are actively restricting that food versus those who eat intuitively and don't restrict foods since we know when a food is 'forbidden,' it makes us want it even more. If you've experienced a change (or no change) in your cravings around your period since adopting intuitive eating, I would love to hear from you in the comments section!
What about the effect of hormonal birth control?
Birth control comes in different forms including pills, injections, rings, and intrauterine devices (IUDs). They may include estrogen and progesterone together, or progesterone only. They essentially work by stabilizing your hormones so there is no spike in hormones that lead to a release of the egg, among other mechanisms.
So there is some thought that progesterone leads to an increase in metabolic rate and appetite so you would think the pills and other areas would cause this increase but we don’t really have a clear picture in the research. One study did show women taking oral contraception containing estrogen and progesterone had a 5% higher metabolic rate than those not taking contraception but this hasn't been replicated in other research. Another study found no difference in metabolic rate with birth control, although this was progesterone only injection, not combination pills.
There are a lot of conflicting studies in this area. Some research says metabolic rate goes up in those using hormonal birth control, some says it stays the same, and a few studies show a decrease in metabolic rate. The results are also mixed for energy intake. Part of this may be due to different timing in taking measurements in terms of menstrual phase but overall, we don't have enough evidence to say metabolism changes one way or the other.
Yet again, pay attention to your body's cues! If you feel more physically hungry, that's a sign to eat, whether you're on the pill or not!
If you feel more hungry before your period, then feed that hunger and eat! I find it so interesting how we try in the research to find out what our energy needs are, how they change, etc. when in reality, our body is pretty amazing at this on its own if we just learn to pay attention to our cues!
I'm not writing this to tell you that you need to eat an extra xxx calories before your period, rather to show you that you can trust your body when you're feeling more hungry! If you find you're not more hungry then don't make yourself eat more either- every person is different in terms of their needs. You don't need fancy equations to tell you how much you need to eat, you just need to learn to listen to your body's cues!
If you're struggling with your eating and your relationship with food and want help, you can find more information on working with me here or you can sign up for my email list here.
Remember- trust your body, it knows what it's doing!